The team, which is based at NASA's Goddard Space Flight Center in
Greenbelt, Md., won a $100,000 study grant to look into three
different techniques for using laser light beams to collect and
move particles, much the same way, albeit on a much smaller
scale, than the fictional Starship Enterprise, of television’s
"Star Trek" series, used tractor beams to shift wayward asteroids
or latch on to visiting vessels.

"You grab whatever particles you can when you fly through the
comet and you bring them home. If you have a spacecraft following
a comet and continuously grabbing particles can study the state
of the comet, or whatever, over time," he said.

He and two colleagues want to figure out which of three
techniques is best suited for collecting samples and perhaps
build the skeleton of a machine to do the job.

One technique, the team says now least-promising, uses Bessel
beams, which is a beam that has rings of light around its central
point. Scientists believe the beams, which look like ripples in
water, could trigger electric and magnetic fields in the path of
an object. In theory, particles would move backward as they bump
into the fields, as described by a team of Chinese and Hong Kong
scientists in a paper published on the electronic archive
arXiv.org in February. The concept has not yet been demonstrated
in a lab.

Another technique uses a pair of beams to work like optical
tweezers. If the beams come from opposite directions, they create
a ring-like field that traps particles where they overlap.
Strengthening or weakening one beam’s intensity causes air around
the trapped particle to heat or cool, causing it to move.

The idea, proposed in 1986 and prototyped by the University of
Chicago in 1997, has been tested as a way to move tiny objects on
microchip and to create new types of photonic devices, such as
optical microscopes and computers that run on light. Currently,
this technique, the most mature the batch, wouldn't work without
an atmosphere, even a puny one like the one on Mars.

The third idea, called optical solenoid beams, would work in a
vacuum. It entails tilting electromagnetic waves to induce motion
in particles.

The project is among 30 pioneering technologies selected by NASA
for study grants and a new program to explore far-out ideas.

"It's essentially the first analysis to see if a revolutionary
concept is feasible," Jay Falker, who oversees the NASA
Innovative Advanced Concepts program at agency headquarters in
Washington DC, told Discovery News.

The agency, which received more than 700 proposals, expects to
decide next year which projects will receive follow-on grants for
additional work. Stysley intends for his team to be among them.

"We're reasonably confident that something could be created that
could be used on a future mission," Stysley said.